Glossary · Mailboxes
Custom domain email is an address on a domain you own, like you@yourcompany.com, instead of a free provider's domain.
You register the domain, choose a provider to host the mailboxes, and point the domain's MX records at it, along with SPF, DKIM and DMARC so your mail is trusted.
Beyond looking professional, it's portable: the address belongs to you, so you can change providers without changing it. With SuperMailOS, every domain you run sits in one inbox, and the DNS records are generated for you.
Every domain you run in one inbox, from $3 a mailbox. 14 days free, no card.